Basic Electrical Awareness

Question 1

Explain the term, ‘Step Potential’ in relation to incidents where electricity is a risk:

Answer 1

Energised wires create a ‘ripple effect’ when it comes in contact with the ground.

When feet are placed on different voltage rings, electricity equal to the difference between the rings will flow through the body.

Question 2

List the two (2) basic forms of how electricity is generated, transmitted and distributed:

Answer 2

• Alternating Current (AC)
• Direct Current (DC)

Question 3

What is the safe approach distance for a fallen (distribution) power line?

Answer 3

8 meters

Question 4

When attending incidents involving Extra High Voltage (EHV) transmission easements, what is the safe approach distance for downed wires?

Answer 4

20 meters

Question 5

Name the wire that connects from the powerline to the point of entry fuse?

Answer 5

Service line/wire

Question 6

What does the acronym UPS stand for?

Answer 6

Uninterruptable Power Supply

Question 7

List the hazards that may be associated with attending an incident in a substation:

Answer 7

1. Confined space
2. High voltage (HV) electricity
3. Compressed gas (FS6 and FM200 displace oxygen)
4. Oil used for cooling - use foam to extinguish
5. Residual power after isolation - in the capacitor banks
6. Hazardous chemicals